Change App icon for debug version to distinguish from store release

[dhcgn]

Currently, it's difficult to distinguish between the app installed from the store and a side-loaded debug version. To avoid confusion, the app icon for the debug version should be changed (e.g., use a badge, overlay, or alternate color) so that users can easily differentiate between the debug and release/store builds.

Acceptance Criteria:

• The debug build of the app uses a clearly distinct icon from the release/store version
• The change is only applied for debug/sideload builds (does not affect the store release icon)
• Optionally: Document the steps for customizing the debug icon in the repository (e.g., in README or relevant doc)

This will help testers and developers avoid confusion when multiple builds are installed on the same device.